272 research outputs found

    Modelling Customers’ Perception of the Quality of Services Provided by Builders: A Case of Victoria, Australia

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    Consumer satisfaction is essential for quality assurance, business survival and economic prosperity. It can also be used as an indicator of the occurrence of defects in the houses delivered by builders. The objective of this study is to compare the quality of services provided by volume and small builders, and to develop a model for predicting the chance of occurrence of structural defects in houses. A list of home builders was obtained from Australia’s Housing Industry Association media release 2019. Thereafter, customer reviews of 10 volume builders and 107 small builders were obtained from publicly available data. Overall, 2336 reviews for volume-builders and 2037 reviews for small builders were analysed quantitatively. Further, using the scores provided by customers, the probability-based regression model for the structural integrity of residential buildings was developed. Generally, the research found that for volume-builders, customers have the highest satisfaction level for ‘customer service’ and the lowest satisfaction level for ‘plumbing and waterproofing’ work. However, for small builders, customers have the highest confidence in the ‘structural integrity’ of their buildings and the least confidence in projects ‘timeliness’. Clients can use the stochastic-based model to predict the probability that a builder could deliver a house with low structural defects. The model showed that if a customer service score for a particular builder is less than 3.3, then there is a higher chance of having structural defects. This research contributes to the body of knowledge by developing and validating the logistic regression model that can be used as a tool to assess the quality of services provided by home builders. Moreover, the research provides useful information which can assist builders to improve the quality of services they provide

    Extended BEG Model of Monhalogenated Methanes Physisorbed on Ionic Crystals

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    The 2D dielectric phases and phase transitions of adsorbed dipolar molecules are modeled using a dilute spin-one Ising model. This model is studied in the Blume–Emery–Griffiths formalism, using a mean-field approximation, where the interaction parameters are uniquely determined from the system interaction energies using an averaging procedure. The model is applied to four monhalogenated methane species physisorbed on MgO(1 0 0) and NaCl(1 0 0) surfaces using previous experimental and theoretical studies to estimate the interaction energy parameters. We find that temperature- and coverage-dependent antiferroelectric to ferroelectric, coverage-dependent ferroelectric up to ferroelectric down, reentrant ferroelectric to ferrielectric, and order-disorder dipole phase transitions can occur. Phase diagrams based on this model are presented

    High-velocity power training has similar effects to traditional resistance training for functional performance in older adults: a systematic review

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    What is the effect of high-velocity power training (HVPT) compared with traditional resistance training (TRT) on functional performance in older adults? What is the quality of intervention reporting for the relevant literature? Systematic review and meta-analysis of randomised controlled trials. Older adults (aged > 60 years), regardless of health status, baseline functional capacity or residential status. High-velocity power training with the intent to perform the concentric phase as quickly as possible compared with traditional moderate-velocity resistance training performed with a concentric phase of ≥ 2 seconds. Short Physical Performance Battery (SPPB), Timed Up and Go test (TUG), five times sit-to-stand test (5-STS), 30-second sit-to-stand test (30-STS), gait speed tests, static or dynamic balance tests, stair climb tests and walking tests for distance. The quality of intervention reporting was assessed with the Consensus on Exercise Reporting Template (CERT) score. Nineteen trials with 1,055 participants were included in the meta-analysis. Compared with TRT, HVPT had a weak-to-moderate effect on change from baseline scores for the SPPB (SMD 0.27, 95% CI 0.02 to 0.53; low-quality evidence) and TUG (SMD 0.35, 95% CI 0.06 to 0.63; low-quality evidence). The effect of HVPT relative to TRT for other outcomes remained very uncertain. The average CERT score across all trials was 53%, with two trials rated high quality and four rated moderate quality. HVPT had similar effects to TRT for functional performance in older adults, but there is considerable uncertainty in most estimates. HVPT had better effects on the SPPB and TUG, but it is unclear whether the benefit is large enough to be clinically worthwhile. [Abstract copyright: Copyright © 2023 Australian Physiotherapy Association. Published by Elsevier B.V. All rights reserved.

    Genetic test to stop smoking (GeTSS) trial protocol: randomised controlled trial of a genetic test (Respiragene) and Auckland formula to assess lung cancer risk

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    Background: A gene-based estimate of lung cancer risk in smokers has been shown to act as a smoking cessation motivator in hospital recruited subjects. The objective of this trial is to determine if this motivator is as effective in subjects recruited from an NHS primary care unit. Method/Design: Subjects will be recruited by mailings using smoking entries on the GP electronic data-base (total practice population = 32,048) to identify smokers who may want to quit. Smoking cessation clinics based on medical centre premises will run for eight weeks. Clinics will be randomised to have the gene-based test for estimation of lung cancer risk or to act as controls groups. The primary endpoint will be smoking cessation at eight weeks and six months. Secondary outcomes will include ranking of the gene-based test with other smoking cessation motivators. Discussion: The results will inform as to whether the gene-based test is both effective as motivator and acceptable to subjects recruited from primary care. Trial registration: Registered with Clinical Trials.gov, Registration number: NCT01176383

    Materials Characterization at Utah State University: Facilities and Knowledgebase of Electronic Properties of Materials Applicable to Spacecraft Charging

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    In an effort to improve the reliability and versatility of spacecraft charging models designed to assist spacecraft designers in accommodating and mitigating the harmful effects of charging on spacecraft, the NASA Space Environments and Effects (SEE) Program has funded development of facilities at Utah State University for the measurement of the electronic properties of both conducting and insulating spacecraft materials. We present here an overview of our instrumentation and capabilities, which are particularly well suited to study electron emission as related to spacecraft charging. These measurements include electron-induced secondary and backscattered yields, spectra, and angular resolved measurements as a function of incident energy, species and angle, plus investigations of ion-induced electron yields, photoelectron yields, sample charging and dielectric breakdown. Extensive surface science characterization capabilities are also available to fully characterize the samples in situ. Our measurements for a wide array of conducting and insulating spacecraft materials have been incorporated into the SEE Charge Collector Knowledgebase as a Database of Electronic Properties of Materials Applicable to Spacecraft Charging. This Database provides an extensive compilation of electronic properties, together with parameterization of these properties in a format that can be easily used with existing spacecraft charging engineering tools and with next generation plasma, charging, and radiation models. Tabulated properties in the Database include: electron-induced secondary electron yield, backscattered yield and emitted electron spectra; He, Ar and Xe ion-induced electron yields and emitted electron spectra; photoyield and solar emittance spectra; and materials characterization including reflectivity, dielectric constant, resistivity, arcing, optical microscopy images, scanning electron micrographs, scanning tunneling microscopy images, and Auger electron spectra. Further details of the instrumentation used for insulator measurements and representative measurements of insulating spacecraft materials are provided in other Spacecraft Charging Conference presentations. The NASA Space Environments and Effects Program, the Air Force Office of Scientific Research, the Boeing Corporation, NASA Graduate Research Fellowships, and the NASA Rocky Mountain Space Grant Consortium have provided support

    Thermodynamic Limits on Magnetodynamos in Rocky Exoplanets

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    To ascertain whether magnetic dynamos operate in rocky exoplanets more massive or hotter than the Earth, we developed a parametric model of a differentiated rocky planet and its thermal evolution. Our model reproduces the established properties of Earth's interior and magnetic field at the present time. When applied to Venus, assuming that planet lacks plate tectonics and has a dehydrated mantle with an elevated viscosity, the model shows that the dynamo shuts down or never operated. Our model predicts that at a fixed planet mass, dynamo history is sensitive to core size, but not to the initial inventory of long-lived, heat-producing radionuclides. It predicts that rocky planets larger than 2.5 Earth masses will not develop inner cores because the temperature-pressure slope of the iron solidus becomes flatter than that of the core adiabat. Instead, iron "snow" will condense near or at the top of these cores, and the net transfer of latent heat upwards will suppress convection and a dynamo. More massive planets can have anemic dynamos due to core cooling, but only if they have mobile lids (plate tectonics). The lifetime of these dynamos is shorter with increasing planet mass but longer with higher surface temperature. Massive Venus-like planets with stagnant lids and more viscous mantles will lack dynamos altogether. We identify two alternative sources of magnetic fields on rocky planets: eddy currents induced in the hot or molten upper layers of planets on very short period orbits, and dynamos in the ionic conducting layers of "ocean" planets with ~10% mass in an upper mantle of water (ice).Comment: Accepted to The Astrophysical Journa

    The NASA-UC Eta-Earth Program: II. A Planet Orbiting HD 156668 with a Minimum Mass of Four Earth Masses

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    We report the discovery of HD 156668b, an extrasolar planet with a minimum mass of M_P sin i = 4.15 M_Earth. This planet was discovered through Keplerian modeling of precise radial velocities from Keck-HIRES and is the second super-Earth to emerge from the NASA-UC Eta-Earth Survey. The best-fit orbit is consistent with circular and has a period of P = 4.6455 d. The Doppler semi-amplitude of this planet, K = 1.89 m/s, is among the lowest ever detected, on par with the detection of GJ 581e using HARPS. A longer period (P ~ 2.3 yr), low-amplitude signal of unknown origin was also detected in the radial velocities and was filtered out of the data while fitting the short-period planet. Additional data are required to determine if the long-period signal is due to a second planet, stellar activity, or another source. Photometric observations using the Automated Photometric Telescopes at Fairborn Observatory show that HD 156668 (an old, quiet K3 dwarf) is photometrically constant over the radial velocity period to 0.1 mmag, supporting the existence of the planet. No transits were detected down to a photometric limit of ~3 mmag, ruling out transiting planets dominated by extremely bloated atmospheres, but not precluding a transiting solid/liquid planet with a modest atmosphere.Comment: This planet was announced at the 2010 AAS meeting in Wash. DC; 12 pages, 8 figures, 3 tables, submitted to Ap

    Age-related degeneration of the lumbar paravertebral muscles: Systematic review and three-level meta-regression

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    This is an author's accepted manuscript of an article published by Elsevier in Experimental Gerontology, available online: https://doi.org/10.1016/j.exger.2020.110856 The accepted manuscript may differ from the final published version.Background: Morphological changes of the lumbar spine muscles are not well characterised with ageing. To further the understanding of age-related degeneration of the lumbar spine musculature, normative morphological changes that occur within the paravertebral muscles must first be established. Methods: A systematic review and meta-regressions were conducted adhering to PRISMA guidelines. Searches for published and unpublished data were completed in June 2019. Results: Searches returned 4781 articles. 34 articles were included in the quantitative analysis. Three-level meta-analyses showed age-related atrophy (r = −0.26; 95% CI: −0.33, −0.17) and fat infiltration (r = 0.39; 95% CI: 0.28, 0.50) in the lumbar paravertebral muscles. Degenerative changes were muscle-specific and men (r = −0.32; 95% CI: −0.61, 0.01) exhibited significantly greater muscle atrophy than women (r = −0.24; 95% CI: −0.47, 0.03). Imaging modality, specifically ultrasound, also influenced age-related muscle atrophy. Measurements taken across all lumbar levels revealed the greatest fat infiltration with ageing (r = 0.58, 95% CI: 0.35, 0.74). Moderators explained a large proportion of between-study variance in true effects for muscle atrophy (72.6%) and fat infiltration (79.8%) models. Conclusions: Lumbar paravertebral muscles undergo age-related degeneration in healthy adults with muscle, lumbar level and sex-specific responses. Future studies should use high-resolution imaging modalities to quantify muscle atrophy and fat infiltration.AD was funded supported Coventry University and University Hospitals Coventry and Warwickshire. This research was carried out with the support of the National Institute of Health Research (NIHR) Coventry and Warwickshire Clinical Research Facility.Published versio

    A comparison of self-reported and device measured sedentary behaviour in adults: a systematic review and meta-analysis

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    © 2020 The Authors. Published by BMC. This is an open access article available under a Creative Commons licence. The published version can be accessed at the following link on the publisher’s website: https://doi.org/10.1186/s12966-020-00938-3BACKGROUND:Sedentary behaviour (SB) is a risk factor for chronic disease and premature mortality. While many individual studies have examined the reliability and validity of various self-report measures for assessing SB, it is not clear, in general, how self-reported SB (e.g., questionnaires, logs, ecological momentary assessments (EMAs)) compares to device measures (e.g., accelerometers, inclinometers). OBJECTIVE:The primary objective of this systematic review was to compare self-report versus device measures of SB in adults. METHODS:Six bibliographic databases were searched to identify all studies which included a comparable self-report and device measure of SB in adults. Risk of bias within and across studies was assessed. Results were synthesized using meta-analyses. RESULTS:The review included 185 unique studies. A total of 123 studies comprising 173 comparisons and data from 55,199 participants were used to examine general criterion validity. The average mean difference was -105.19 minutes/day (95% CI: -127.21, -83.17); self-report underestimated sedentary time by ~1.74 hours/day compared to device measures. Self-reported time spent sedentary at work was ~40 minutes higher than when assessed by devices. Single item measures performed more poorly than multi-item questionnaires, EMAs and logs/diaries. On average, when compared to inclinometers, multi-item questionnaires, EMAs and logs/diaries were not significantly different, but had substantial amount of variability (up to 6 hours/day within individual studies) with approximately half over-reporting and half under-reporting. A total of 54 studies provided an assessment of reliability of a self-report measure, on average the reliability was good (ICC = 0.66). CONCLUSIONS:Evidence from this review suggests that single-item self-report measures generally underestimate sedentary time when compared to device measures. For accuracy, multi-item questionnaires, EMAs and logs/diaries with a shorter recall period should be encouraged above single item questions and longer recall periods if sedentary time is a primary outcome of study. Users should also be aware of the high degree of variability between and within tools. Studies should exert caution when comparing associations between different self-report and device measures with health outcomes. SYSTEMATIC REVIEW REGISTRATION:PROSPERO CRD42019118755.Dr. Stephanie Prince was funded by a Canadian Institutes of Health Research (CIHR) – Public Health Agency of Canada Health System Impact Fellowship. Dr. Jennifer Reed is funded, in part, by a CIHR New Investigator Salary Award. Dr. Jennifer Reed was awarded a Planning and Dissemination Grant (#150435) from the CIHR to support Open Access publication charges.Published versio
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